eval_toolkit.provenance

FileHash	Sentinel-style hit for a successful file hash.
FileHashMissing	Sentinel-style miss for a file hash that could not be computed.
capture_git_sha	Current HEAD full SHA, or None if not in a git repo.
compute_file_hash	SHA-256 hex digest of an existing file (sentinel-typed).
figure_metadata	Build a JSON-serializable provenance dict for save_figure.
file_sha256	SHA-256 hex digest of an existing file.
make_run_dir	Create and return a timestamped run directory.